1. Field
This disclosure relates generally to data processing systems, and more specifically, to data acquisition messaging for debugging data processing systems.
2. Related Art
Traditionally, data acquisition for an external debugger has been achieved using software writes to appropriate locations in a memory. As part of this traditional process, the external debug module supplies an address to be used to monitor data values of interest. That address is then stored in the user base address (UBA) register. The debug logic associated with a data processing system then compares the addresses being accessed to the address stored in the UBA. If there is a match, the debug logic then provides data corresponding to the address to the external debugger in the form of a data acquisition message.
The traditional data acquisition process has several disadvantages. First, the traditional data acquisition process requires an address comparison. If the address of interest is a virtual address, then the address comparison has to happen before the memory management unit address translation and thus could be speculative. Second, the traditional data acquisition process requires access to the memory subsystem, which can result in the cache being impacted by the debug process. For example, a cache miss may occur as a result of data movement out of the cache when the memory subsystem is accessed.
Accordingly, there is a need for improved data acquisition messaging for debugging data processing systems.